But take it easy on Stone and Hathaway. Emerging research suggests that, at least for some, the ability to imitate an accent may be innate, related to the shape of the brain's auditory cortex.

Neurologist Sophie Scott recently published a study that looked at images of the brains of phoneticians, specialists in phonetics who are able to pick up very subtle differences to regional accents. Through these brain scans, called magnetic resonance imaging, Scott and a team of neuroscientists found differences between the phoneticians and the non-phonetician control group in the shape of the left auditory cortex -- a part of the brain that's developed before birth.

"So I'm sure we won't only find this with phonetics; it's possible that impressionists will have this as well," Scott told the Guardian last month. "It does suggest a biological explanation as to why some people might find the world of sound and speech more interesting."

It's true that with practice, almost anyone can at least improve their ability to imitate accents, says Dr. Amee P. Shah, associate professor and research director in Cleveland State University's speech and hearing program. But Shah, who has taught workshops on "accent modification," says some people she works with, who want a flat, "American" accent, easily pick it up within a few sessions; others struggle for weeks.

Shah also points out that when we're talking actors, accent mimicry goes hand in hand with "how well they're imitating everything about a person. ... Research does show that (mimicry ability) correlates with someone's ability to do good acting," Shah says. Ouch, Stone and Hathaway. Ouch.

What's the worst movie accent you can remember? Leave a comment complaining away.